Substrate processing apparatus

ABSTRACT

A substrate processing apparatus is provided. The apparatus includes a plurality of fluid suppliers  61, 61, 63  for supplying different processing fluids. In processing a wafer W, the substrate processing apparatus moves the fluid suppliers  61, 62, 63  along the peripheral part of the wafer W relatively. The fluid suppliers  61, 62, 63  are arranged in a direction extending from the circumference of the wafer W to its inside. With the arrangement, the apparatus is capable of stable processing of the wafer W in spite of rotating the wafer W at a low speed. Further, it is possible to improve a throughput of the apparatus in resist processing.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a division of Ser. No. 11/356,364 filed Feb. 17,2006, which is a division of Ser. No. 10/209,617, filed Aug. 1, 2002 nowU.S. Pat. No. 7,332,055, both being incorporated in their entiretyherein by reference.

BACKGROUND OF THE INVENTION

1. Technical Field of the Invention

This invention relates to substrate processing apparatus for processingsubstrates, for example, semiconductor wafers, glass substrates for LCD,etc.

2. Description of the Related Art

In the manufacturing process for semiconductor devices, there exists aproblem that when a semiconductor wafer (referred as “wafer”,hereinafter) has a metallic film laminated thereon, the metallic film iseasy to separate from the peripheral part of the wafer. If such aseparation originates in the peripheral part of the wafer, theseparation may spread gradually to extend over an area where asemiconductor device is to be built. In order to prevent the occurrenceof the above phenomenon, there has been attempted a step of removing ametallic film (part) formed on the peripheral part of the wafer inadvance. Note, this removal step will be referred “peripheral-partremoving process”, hereinafter. FIG. 21 is an explanatory view of amethod of carrying out the peripheral-part removing process by using theconventional substrate processing apparatus. According to the method, awafer W is rotated by a holder. While rotating the wafer W, a processingliquid is supplied to the peripheral part of the wafer W through aliquid supplier 140, such as nozzle, thereby to eliminate thecircumferential corner of a metallic film 141 obliquely. On the otherhand, through a supply unit 142 arranged above the center of the waferW, pure water is supplied to the wafer W in order to prevent theprocessing liquid from adhering to the other wafer portion except anobjective area to be supplied with the processing liquid and also orderto sweep away the processing liquid toward the circumference of thewafer.

In order to produce enough centrifugal force to sweep away theprocessing liquid toward the circumference of the wafer, however, it hasbeen required that the substrate processing apparatus can rotate thewafer at considerable high-speed revolutions. Additionally, as the purewater is supplied to the whole wafer in spite of processing theperipheral part of the wafer only, the whole wafer has to be driedthroughout. Therefore, these requirements incur a deterioration in thethroughput of the substrate processing apparatus in processing thewafers.

SUMMARY OF THE INVENTION

Under such a circumference as mentioned above, an object of the presentinvention is to provide substrate processing apparatus which is capableof stable processing in spite of rotating the substrate at a low speedand also capable of improving the above throughput.

In order to attain the above object, according to the first feature ofthe present invention, there is provided a substrate processingapparatus for processing a substrate, comprising:

-   -   a plurality of fluid suppliers arranged apart from each other in        the vicinity of the peripheral part of the substrate and adapted        so as to supply the substrate with difference processing fluids,        the fluid suppliers being arranged in one line extending from        the circumference of the substrate toward an inside thereof;    -   wherein the processing fluids are supplied from the plural fluid        suppliers to the peripheral part of the substrate while rotating        the substrate thereby to allow the plurality of fluid suppliers        to move along the circumference of the substrate relatively.        According to this substrate processing apparatus, the processing        fluid supplied from the inside fluid supplier (in the radial        direction of the substrate) allows the other processing fluid,        such as chemical liquid, supplied from the outside fluid        supplier to be swept away in a direction apart from the center        of the substrate.

According to the second feature of the invention, a top plate isarranged above the substrate so as to oppose the substrate. The topplate is relatively movable between a position adjacent to the top faceof the substrate and a position apart from the top face of thesubstrate. For example, at processing, if moving the top plate to aposition close to the upper face of the substrate thereby to cover asubstrate's surface requiring no processing, then it becomes possible toprevent the processing fluid from splashing onto the above substrate'ssurface requiring no processing.

According to the third feature of the invention, the top plate has adiameter smaller than a diameter of the substrate.

According to the fourth feature of the invention, the top plate isadapted so as to eject inert gas between the top plate and thesubstrate.

According to the fifth feature of the invention, the top plate isrotatable.

According to the sixth feature of the invention, the top plate isprovided, on a peripheral part thereof, with a recess for receiving theplural fluid suppliers therein. For example, at processing, if theplural fluid suppliers supply the processing fluids while being receivedin the recess, the top plate can cover the other surface on thesubstrate.

According to the seventh feature of the invention, an under plate isarranged below the substrate. The under plate is movable up and down andarranged so as to oppose the substrate.

According to the eighth feature of the invention, the under plate has aport formed to supply a cleaning liquid for cleaning the substrate.

According to the ninth feature of the invention, the plural fluidsuppliers are movable in relation to the substrate along a direction toarrange the fluid suppliers.

According to the tenth feature of the invention, the substrateprocessing apparatus further comprises an outer chamber which isarranged so as to surround the substrate and the plural fluid suppliersare movable between an inside of the outer chamber and the outside.

According to the eleventh feature of the invention, the substrateprocessing apparatus further comprises a supplier housing which isarranged outside the outer chamber to house the plural fluid supplierstherein.

According to the twelfth feature of the invention, the plural fluidsuppliers are controlled in operation so that an inside fluid supplierof the fluid suppliers supplies the processing fluid in advance of thesupply of the processing fluid by an outside fluid supplier of the fluidsuppliers, the inside fluid supplier being closer to the center of thesubstrate than the outside fluid supplier.

According to the thirteenth feature of the invention, an outermost fluidsupplier of the plural fluid suppliers is adapted so as to supply thesubstrate with a chemical liquid, while an innermost fluid supplier ofthe plural fluid suppliers is adapted so as to supply the substrate withan inert processing fluid.

According to the fourteenth feature of the invention, the inertprocessing fluid is a nitrogen gas, a pure water flowing between thechemical liquid and the nitrogen gas.

In this case, since the innermost fluid supplier does not process thesubstrate, the pure water can sweep away a processing liquid supplied tothe peripheral part of the substrate without processing the centersurface of the substrate.

According to the fifteenth feature of the invention, the chemical liquidis a liquid for removing a metallic film formed on the substrate.

According to the sixteenth feature of the invention, the processingfluid supplied from an exterior one of the plural fluid suppliers issupplied in a flowing area where the processing fluid supplied from aninterior one of the plural fluid suppliers is flowing on the surface ofthe substrate. Then, by the processing fluid supplied from the insidefluid supplier (in the radial direction of the substrate), it ispossible to prevent the other processing fluid supplied from the outsidefluid supplier from flowing outside of a substrate's surface (area)where the processing fluid from the inside fluid supplier is flowing on.

According to the seventeenth feature of the invention, the plural fluidsuppliers are provided with a common cover plate for preventing theprocessing fluids ejected from the fluid suppliers from splashing to thecenter side of the substrate.

According to the eighteenth feature of the invention, the substrateprocessing apparatus further comprises an annular cover which isarranged in the circumference of the substrate to receive the processingfluids which has been supplied to the substrate in rotation andsubsequently splashed due to resultant centrifugal force.

According to the nineteenth feature of the invention, the processing ofthe substrate is carried out in multistage in accordance with a distancefrom the periphery of the substrate.

According to the twentieth feature of the invention, the top plate isarranged above the substrate so as to oppose the substrate, wherein thetop plate is relatively movable between a position adjacent to the topface of the substrate and a position apart from the top face of thesubstrate, the top plate being adapted so as to eject inert gas betweenthe top plate and the substrate, wherein the plural fluid suppliers aremovable in relation to the substrate along a direction to arrange thefluid suppliers.

According to the twenty-first feature of the invention, the under plateis arranged below the substrate so as to oppose the substrate and ismovable up and down, the under plate having a port formed to supply acleaning liquid for cleaning the substrate.

According to the present invention, there is also provided a substrateprocessing method of relatively moving a plurality of fluid suppliersarranged in one line extending from the circumference of the substratetoward an inside thereof and supplying the peripheral part of thesubstrate with different processing fluids from the plural fluidsuppliers thereby processing the substrate. This method is characterizedin that the processing fluid supplied by the inside fluid suppliersweeps away the other processing fluid supplied by the outside fluidsupplier in a direction apart from the center of the substrate.

In the plural fluid suppliers, preferably, the outermost fluid supplieris adapted so as to supply the substrate with a chemical liquid, whilethe innermost fluid supplier is adapted so as to supply the substratewith an inert processing fluid. Additionally, the innermost fluidsupplier may supply the substrate with pure water.

In the above substrate processing method, it is desirable that theplural fluid suppliers are controlled in operation so that the insidefluid supplier supplies the processing fluid in advance of the supply ofthe processing fluid by the outside fluid supplier. Note, the insidefluid supplier is arranged closer to the center of the substrate thanthe outside fluid supplier.

Further, it is preferable to move the plural fluid suppliers along adirection to arrange the fluid suppliers. Then, it becomes possible tochange a width of each processed area on the substrate. Further, inmoving the plural fluid suppliers, it is desirable that the processingof the substrate using the different processing fluids is carried out inmultistage in accordance with a distance from the periphery of thesubstrate.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a plan view of a substrate processing system;

FIG. 2 is a side view of the substrate processing system;

FIG. 3 is a sectional showing the schematic arrangement of a waferdelivery unit, a main wafer transfer device, a heating unit and acooling unit all forming the substrate processing system;

FIG. 4 is a plan view of a substrate processing unit of an embodiment ofthe present invention;

FIG. 5 is an explanatory view of an edge arm;

FIG. 6 is an explanatory view showing respective wafer's surfaces towhich respective processing liquids are supplied from a chemical-liquidnozzle, a pure-water nozzle and a N₂-gas nozzle and also respectivewafer's surfaces on which the processing liquids flow subsequently tothe supply;

FIG. 7 is a sectional view of the processing system of the embodiment ofthe invention;

FIG. 8 is an explanatory view showing the state of a holding member at astandstill;

FIG. 9 is an explanatory view showing the state of the holding memberwhen rotating at a middle speed;

FIG. 10 is an explanatory view showing the state of the holding memberwhen rotating at a high speed;

FIG. 11 is a longitudinal sectional view of an under plate and anunder-plate shaft;

FIG. 12 is a plan view of the under plate;

FIG. 13 is a longitudinal sectional view showing an enlarged top part ofan outer chamber;

FIG. 14 is an explanatory view of a process of discharging droplets inan inner cup to a mist trap;

FIG. 15 is an explanatory view of a process of discharging droplets inthe outer chamber to the mist trap;

FIG. 16 is an explanatory view of a process of paddle-cleaning the backface of the wafer;

FIG. 17 is an explanatory view of a process of removing the peripheralpart of the wafer;

FIG. 18 is an explanatory view showing another top plate in themodification;

FIG. 19 is an explanatory view showing the substrate processing unit ofthe embodiment equipped with a fan filter unit (FFU) and an exhaustmechanism;

FIG. 20 is an explanatory view of a process of removing the peripheralpart of the wafer in accordance with another embodiment of theinvention; and

FIG. 21 is an explanatory view of a process of removing the peripheralpart of the wafer in the substrate processing apparatus.

DESCRIPTION OF THE PREFERRED EMBODIMENT

Based on a substrate processing unit (as the substrate processingapparatus) which is constructed so as to clean the peripheral part of awafer (as the substrate) and its back face, one preferred embodiment ofthe present invention will be described below. In the followingdescriptions, a word “cleaning process” contains a cleaning operation toeliminate a film deposited on a substrate. FIG. 1 is a plan view of thecleaning system 1 having built-in substrate processing units 12, 13 ofthe embodiment. FIG. 2 is a side view of FIG. 1. The cleaning system 1includes a cleaning part 2 for carrying out cleaning process for wafersW and sequent heat treatment after cleaning and a loading/unloading part3 for loading and unloading the wafers W to and from the cleaning part2.

The loading/unloading part 3 is formed by an in/out port 4 provided witha mounting table 6 for mounting a container (carrier C) thereon and awafer-transfer part 5 equipped with a wafer transfer unit 7 for carryingout the delivery of wafer between the carrier C mounted on the mountingtable 6 and a cleaning part 2. The carrier C is capable of accommodatinga plurality of wafers W (for example, twenty-five wafers) generallyhorizontally, at predetermined intervals.

The wafers W are loaded or unloaded through one side face of the carrierC. The carrier C is provided, on the side face, with a lid body that canopen and shut the carrier. The carrier C has a plurality of shelf platesformed on its inner wall to retain the wafers W thereon at predeterminedintervals, providing twenty-five slots for accommodating the waferstherein. While positioning the wafers' surfaces (i.e. surfaces forforming semiconductor devices) so as to face upward, the wafers W areaccommodated in the slots, one by one.

The mounting table 6 of the in/out port 4 is capable of mounting e.g.three carriers C juxtaposed in a direction Y on the horizontal plane ofthe table, at predetermined positions. The carriers C are mounted on thetable 6 so that their side faces having the lid bodies face a boundarywall 8 between the in/out port 4 and the wafer transfer part 5. Theboundary wall 8 is provided, at positions corresponding to the mountingpositions of the carriers C, with windows 9. On each window's sidefacing the wafer transfer part 5, there is arranged a window openingmechanism 10 that opens and closes the corresponding window 9 by meansof a shutter etc.

This window opening mechanism 10 is also capable of opening and closingthe lid body of the carrier C. The window opening mechanism 10 opens orcloses the lid body of the carrier C at the same time of opening orclosing the window 9. Preferably, the window opening mechanism 10 isprovided with an interlocking unit that prohibits the mechanism fromoperating when the carrier C is not arranged at a designated position onthe mounting table. When the window 9 is opened to communicate theloading/unloading port of the carrier C with the wafer transfer part 5,it becomes possible for the wafer transfer unit 7 in the wafer transferpart 5 to gain access to the carrier C, allowing of the transportationof the wafer W. On the top of the window 9, a not-shown wafer detectingdevice is arranged to detect the number of wafers W accommodated in thecarrier C and also their conditions every slot. Alternatively, the waferdetecting device may be equipped with the window opening mechanism 10.

The wafer transfer unit 7 in the wafer transfer part 5 is movable inboth Y-direction and Z-direction and also rotatable in a plane of X-Y(è-direction). The wafer transfer unit 7 includes a pickup/accommodatingarm 11 for grasping the wafer W. The pickup/accommodating arm 11 isslidable in a direction of X. In this way, the wafer transfer unit 7 canobtain access to a slot at any height of all the carriers C mounted onthe mounting table 6 and also access to two upper and lower waferdelivery units 16, 17 arranged in the cleaning part 2, allowing thewafer W to be transferred from the in/out port 4 to the cleaning part 2,and vice versa.

The cleaning part 2 includes a main wafer transfer unit 18, two waferdelivery units 16, 17, two substrate processing units 12, 13 of thisembodiment, substrate cleaning units 14, 15, three heating units 19, 20,21 for heating the wafers W to dry them and a cooling unit 22 forcooling the heated wafers W. The main wafer transfer unit 18 is arrangedto give access to all of the wafer delivery units 16, 17, the substrateprocessing units 12, 13, the substrate cleaning units 14, 15, theheating units 19, 20, 21 and also the cooling unit 22. In order toaccomplish the delivery of the wafers W between the wafer transfer part5 and the wafer delivery units 16, 17, the wafers W are temporarilymounted on the units 16, 17.

In the cleaning part 2, there are arranged a battery unit 23 as a powersource for working the whole cleaning system 1, a mechanical controlunit 24 for controlling the operations of various sorts of devices inthe cleaning system 1 and also the operation of the system 1 as a wholeand a chemical storage unit 24 for storing designated cleaning liquidsto be supplied to the substrate processing units 12, 13 and also thesubstrate cleaning units 14, 15. The battery unit 23 is connected with anot-shown main power source. On the ceiling part of the cleaning part 2,a fan filter unit (FFU) 26 is arranged to supply the above units and themain wafer transfer unit 18 with downward-flowing fresh air.

By either arranging the battery unit 23, the chemical storage unit 25and the mechanical control unit 24 outside the cleaning part 2 orwithdrawing these units 23, 24, 25 from the part 2, the arrangementfacilitates maintenance of the wafer delivery units 16, 17, the mainwafer transfer unit 18, the heating units 19, 20, 21 and also thecooling unit 22, from this plane (Y-direction).

FIG. 3 is a sectional view showing the schematic arrangement of thewafer delivery units 16, 17, the main wafer transfer unit 18 adjacent tothe units 16, 17 in the direction X, the heating units 19, 20, 21 andthe cooling unit 22. The wafer delivery units 16, 17 are stacked up intwo stages up and down. For example, the wafer delivery unit 17 on thelower stage is used to mount the wafer W transferred from the in/outport 4 to the cleaning part 2, while the wafer delivery unit 16 on theupper stage is used to mount the wafer W transferred from the cleaningpart 2 to the in/out port 4.

The down ward flow from the fan filter unit (FFU) 26 partially passesthrough the wafer delivery units 16, 17 and also their upside space andflows into the wafer transfer part 5. Consequently, it is possible toprevent particles etc. from invading the cleaning part 2 through thewafer transfer part 2, thereby maintaining the cleanness in the cleaningpart 2.

The main wafer transfer unit 7 includes a cylindrical holder 30extending in the direction of Z and having vertical walls 27, 28 and alateral opening 29 there between and a wafer transfer body 31 disposedin the holder 30 so as to move up and down in the direction of Z. Thecylindrical holder 30 is rotatable owing to the rotational driving forceof a motor 32 and correspondingly, the wafer transfer body 31 is rotatedin a body with the holder 30.

The wafer transfer body 31 is equipped with a transfer base 33 and threetransfer arms 34, 35, 36 movable in front and in the rear along thetransfer base 33. The transfer arms 34, 35, 36 are formed withdimensions allowing the arms to pass through the lateral opening 29 ofthe cylindrical holder 30. These transfer arms 34, 35, 36 are adapted soas to move independently of each other owing to a motor and a beltmechanism both provided in the transfer base 33. When a belt 38 isdriven by a motor 37, the wafer transfer body 31 can move up and down.Note, reference numeral 39 denotes a driving pulley, while referencenumeral 40 denotes a driven pulley.

On the cooling unit 22 for cooling the wafer W by force, the heatingunits 19, 20, 21 are piled up one after another. Alternatively, theremay be arranged the cooling unit 22 and the heating units 19, 20, 21 ina space defined above the wafer delivery units 16, 17. Then, it becomespossible to divert respective spaces occupied by the cooling unit 22 andthe heating units 19, 20, 21 to another utility space.

The substrate processing units 12, 13 are arranged in two stagesvertically. The substrate processing units 12, 13 are capable ofcleaning of the back face of the wafer W, removal of the peripheral partof the surface of the wafer W and also cleaning of the surface of thewafer W (Back-Bevel cleaning). The substrate processing units 12, 13 areprovided with structures similar to each other. Therefore, the detailedstructures will be described below, by example of the substrateprocessing unit 12.

FIG. 4 is a plan view of the substrate processing unit 12. The substrateprocessing unit 12 is provided, in a “unit” chamber 42 thereof, with anouter chamber 43 of closed structure for accommodating the wafer Wtherein, and an “edge arm” housing 44. An opening 45 is formed in the“unit” chamber 42. The “unit” chamber 42 is provided with a mechanicalshutter 46 that opens and closes the opening 45 by means of a not-shownclosing mechanism. When the wafer W is loaded to or unloaded from thesubstrate processing unit 12 through the opening 45 by the transfer arm,the mechanical shutter 46 opens. The mechanical shutter 46 for unitchamber is adapted so as to open and close the opening 45 on theinterior side of the “unit” chamber 42. Thus, even if a positivepressure is formed in the “unit” chamber 42, an atmosphere inside the“unit” chamber 42 can be prevent from leaking out.

An opening 47 is formed in the outer chamber 43. The outer chamber 43 isprovided with a mechanical shutter 48 that opens and closes the opening47 by means of a not-shown cylinder driving mechanism. When the wafer Wis loaded to or unloaded from the outer chamber. 43 through the opening47 by e.g. the transfer arm 34, the mechanical shutter 48 for outerchamber opens. The mechanical shutter 48 for outer chamber is adapted soas to open and close the opening 47 on the interior side of the outerchamber 43. Thus, even if a positive pressure is formed in the outerchamber 43, an atmosphere inside the outer chamber 43 can be preventfrom leaking out.

An opening 49 is formed in the “edge arm” housing 44. The “edge arm”housing 44 is provided with a shutter 50 that opens and closes theopening 49 by means of a not-shown driving mechanism. When the “edgearm” housing 44 is insulated from the outer chamber 43 in terms ofatmosphere therein, the shutter 50 for the edge-arm housing closes. Theshutter 50 for “edge arm” housing is adapted so as to open and close theopening 49 on the interior side of the outer chamber 43. Thus, even if apositive pressure is formed in the “unit” chamber 42, an atmosphereinside the “unit” chamber 42 can be prevent from leaking out.

Accommodated in the “edge arm” housing 44 is an edge arm (unit) 60 whichcan eject a chemical liquid, pure water and also N₂-gas as an inert gas.The edge arm 60 can be also accommodated in the outer chamber 43 and ismovable up to the periphery of the wafer W held by a later-mentionedspin chuck 71. The edge arm 60 takes shelter in the “edge arm” housing44 except the processing operation. If the edge arm 60 moves into theouter chamber 43 through the opening 49, then the shutter 50 for the“edge arm” housing opens.

As shown in FIG. 5, the edge arm 60 includes a chemical nozzle 61 forsupplying the wafer W (metallic membrane 141) with a chemical liquid, apure-water nozzle 62 for supplying the wafer W with pure water as aninert liquid and a N₂-gas nozzle 63 for supplying the wafer W withN₂-gas as inert gas. The chemical nozzle 61, the pure-water nozzle 62and the N₂-gas nozzle 63 are all arranged in one line connecting thecenter of the wafer W with its periphery. That is, according to theshown example, they are arranged in the radial direction of the wafer Win the form of a circular plate. A metallic film 141, such as copper, islaminated on the surface of the wafer W. The chemical nozzle 61 suppliesa chemical liquid for removing the metallic film 141. The pure-waternozzle 62 adjoining on the inside of the chemical nozzle 61 suppliespure water for rinsing the peripheral part of the wafer W. The N₂-gasnozzle 63 adjoining on the inside of the pure-water nozzle. 62 suppliesN₂-gas for drying the peripheral part of the wafer W.

The chemical nozzle 61, the pure-water nozzle 62 and the N₂-gas nozzle63 are held by a cover plate 64 in order to prevent the chemical liquid,the pure water and N₂-gas, which have been supplied through the nozzles61, 62, 63 respectively, from splashing. The chemical nozzle 61, thepure-water nozzle 62 and the N₂-gas nozzle 63 are inclined in adirection apart from the center of the wafer W. In detail, the chemicalnozzle 61, the pure-water nozzle 62 and the N₂-gas nozzle 63 have theirtips directing the outer circumference of the wafer W. On thecircumferential side of the wafer W over the chemical nozzle 61, asuction nozzle 65 is arranged to suck the chemical liquid, the purewater and N₂-gas supplied through the nozzles 61, 62, 63 respectivelyand also an atmosphere produced during the processing.

In case of supplying the chemical liquid to the wafer W by the chemicalnozzle 61, the N₂-gas nozzle 63 begins the supply of N₂-gas in advanceof the supply of the chemical liquid. In this case, as shown in FIG. 6,the N₂-gas nozzle 63 supplies N₂-gas onto an area 68 on the wafer W. TheN₂-gas supplied onto the area 68 flows on the surface of the wafer W(surface of the metallic film 141) in the form of a fan directing theperipheral part of the wafer W, providing a flowing area 68′. On theother hand, the chemical nozzle 61 supplied the chemical liquid onto anarea 66 on the wafer W, so that the chemical liquid supplied to the area66 flows on the wafer W while directing its peripheral part, providing afan-shaped flowing area 66′. These areas 66, 66′ are together includedin the area 68′. Thus, as mentioned before, when the N₂-gas nozzle 63begins the supply of N₂-gas in advance of the supply of the chemicalliquid by the chemical nozzle 61, the chemical liquid is certainlysupplied to the area 66 and subsequently, the same liquid is swept awaytoward the periphery of the wafer W owing to the flowing of N₂-gas inthe form of the area 68′. In this way, there is no fear that thechemical liquid through the chemical nozzle 61 flows toward the centerof the wafer W.

In case of supplying the pure water to the wafer W by the pure-waternozzle 62, the N₂-gas nozzle 63 begins the supply of N₂-gas in advanceof the supply of the pure water. In this case, as shown in FIG. 6, theN₂-gas nozzle 63 supplies N₂-gas onto the area 68 on the wafer W. TheN₂-gas supplied onto the area 68 flows on the surface of the wafer Wwhile directing the periphery of the wafer W, providing the fan-shapedflowing area 68′. On the other hand, the pure-water nozzle 62 suppliedthe pure water onto an area 67 on the wafer W, so that the pure watersupplied to the area 67 flows on the wafer W while directing itsperiphery, providing a fan-shaped flowing area 67′. These areas 67, 67′are together included in the area 68′. Thus, as mentioned before, whenthe N₂-gas nozzle 63 begins the supply of N₂-gas in advance of thesupply of the pure water by the pure-water nozzle 62, the pure water iscertainly supplied to the area 67 and subsequently, the pure water isswept away toward the periphery of the wafer W owing to the flowing ofN₂-gas in the form of the area 68′. In this way, there is no fear thatthe pure water through the pure-water nozzle 62 flows toward the centerof the wafer W. Note, in order to make sure that the chemical liquid andthe pure water are swept away by N₂-gas flowing in the form of the area68′, it is desirable that the area 68 of N₂-gas supply is wider thaneither of the areas 66, 67. Then, it becomes possible to supply N₂-gassuch that a width of the area 68′ in the circumferential direction ofthe wafer W becomes broader than either width of the areas 66′, 67′.

As shown in FIG. 7, the outer chamber 43 includes an inner cup 70 foraccommodating the wafer W, a spin chuck 71 (as a holder) for holding thewafer W rotatably while directing the surface of the wafer W upward anda top plate 72 that moves up and down in relation to the upper face ofthe wafer W (the surface of the wafer W).

The spin chuck 71 includes a chuck body 73 for holding the wafer W and arotating cylinder 74 connected with the bottom of the chuck body 73.Disposed in the chuck body 73 is an under plate 75 which moves up anddown with respect to the under face (back face) of the wafer W held bythe spin chuck 71, relatively.

The upper part of the chuck body 73 is equipped, at several positions,with not-shown support pins for supporting the peripheral part of theback face of the wafer W and holding members 76 for holding theperipheral part of the wafer W. In the shown example, three holdingmembers 76 are arranged at intervals of 120 degrees in the circumferenceof the chuck body 73. Thus, the periphery of the wafer W can be held bythese members 76. Further, the chuck body 73 is provided, at intervalsof 120 degrees in the circumference of the wafer W, with three supportpins which support the wafer W from the underside and which are notshown in the figure. A belt 77 is wound about the circumferential faceof the rotating cylinder 74. Owing to a motor 78, the resultingcircumferential movement of the belt 77 allows the spin chuck 71 to berotated as a whole. As shown in FIG. 4, the holding members 76 areadapted so as to hold the peripheral part of the wafer W from theoutside owing to centrifugal force produced by the rotation of the spinchuck 71. When the spin chuck 71 comes to a standstill, the abovesupport pins support the back face of the wafer W. While, when the spinchuck is rotating, the holding members 76 hold the peripheral part ofthe wafer W.

FIG. 8 shows each structure of the holding members 76 for holding thewafer W. The holding member 76 is formed by a grasping arm 80, a pusherarm 81 and a spring 82. Both of the grasping arm 80 and the pusher arm81 are rotatable about a pivot 83 as the rotating center. The spring 82is interposed between the grasping arm 80 and the pusher arm 81. Thepivot 83 is fixed on the chuck body 73. The pusher arm 81 is provided,at the lowermost, with a weight 84. The rotation of the spin chuck 71causes the weight 84 to be shifted outside by a centrifugal forceapplied thereon, as shown in FIG. 9. Consequently, as the upper part ofthe grasping arm 80 moves inside, it is possible to hold the peripheryof the wafer W. Then, since the spring 82 absorbs so-generated energy,it becomes possible to prevent a pressure to hold the periphery of thewafer W (holding force) from increasing excessively. When the spin chuck71 rotates at high speed, the weight 84 comes in abutment with a stopper85 in the chuck body 73, as shown in FIG. 10. Then, as the spring 82absorbs generated energy, it is possible to a holding force fromincreasing excessively.

The under plate 75 is connected with the top of an under-plate shaft 90penetrating the chuck body 73 and the rotating cylinder 74. Theunder-plate shaft 90 is secured on the upper face of a horizontal plate91. By an elevating mechanism 92, such as cylinder, the horizontal plate91 is moved up and down in the vertical direction, in one body with theunder-plate shaft 90. Accordingly, the under plate 75 can be lowered inthe chuck body 73 into a condition where the plate 75 are waiting inreadiness apart from the under face of the wafer W held by the spinchuck 71 (see FIG. 7; withdrawal position). While, the under plate 75can be also elevated in the chuck body 73 into a condition where theunder face of the wafer W held by the spin chuck 71 is being cleaned(see FIG. 18; processing position). That is, the under plate 75 ismovable up and down between the processing position and the withdrawalposition. Alternatively, there may be provided the under plate 75 whichis movable between the processing position and the withdrawal positionby the following steps of: fixing the under plate 75 at a designatedlevel; connecting the rotating cylinder 74 with a not-shown elevatingmechanism; and moving the whole spin chuck 71 up and down.

The top plate 72 is connected with the lower end of a rotating shaft 95and rotated by a motor 97 mounted on a horizontal plate 96. The rotatingshaft 95 is rotatably supported on the lower face of the horizontalplate 96. The horizontal plate 96 can move up and down in the verticaldirection by a shaft-elevating mechanism 98, such as air cylinder,secured on the top of the outer chamber. Therefore, owing to theoperation of the shaft-elevating mechanism 98, the top plate 72 ismovable up and down between a condition where the plate 72 are waitingin readiness apart from the upper face of the wafer W held by the spinchuck 71 (see FIG. 7; withdrawal position) and another condition wherethe plate 72 adjoins the upper face of the wafer W held by the spinchuck 71 (see FIG. 17; processing position). Further, as shown in FIG.4, since the diameter of the top plate 72 is smaller than that of thewafer W, the edge arm 60 can process the peripheral part of the wafer W.

The inner cup 70 can be lowered to a position of FIG. 7 to allow thespin chuck 71 to project from the upper end of the inner cup 70,establishing a condition that the spin chuck 71 can deliver the wafer W.While, the inner cup 70 can be also elevated to a position of FIG. 17 tosurround the spin chuck 71 and the wafer W, establishing anothercondition to prevent cleaning chemical liquids, processing liquids, etc.supplied on both faces of the wafer W from splashing around.

When it is required to lower the inner cup 70 to the position of FIG. 7thereby to allow the spin chuck 71 to transfer the wafer W, the underplate 75 is positioned at the withdrawal position and the top plate isalso positioned at the withdrawal position. Consequently, there can bedefined a sufficient clearance between the under plate 75 and the waferW held by the spin chuck 71. Additionally, there is also defined asufficient clearance between the top plate 72 and the upper face of thewafer W. In this way, the transfer of the wafer W about the spin chuck71 can be accomplished smoothly.

As shown in FIG. 11, the under plate 75 is provided with a lower supplypath 100 which penetrates the under-plate shaft 90 to supply the lowerface of the wafer W with the processing liquids (e.g. cleaning chemicalliquids, pure water) and dry gas. As shown in FIG. 12, the under plate75 has lower ejection ports 101-105 formed at its center and thesurroundings to eject cleaning chemicals/pure water/N₂-gas. The lowerejection ports 101-104 around the center of the plate 75 are inclinedtoward the periphery of the wafer W, while the center ejection port 105directs the center of the wafer W upward.

As shown in FIG. 13, the top plate 72 is provided with an upper supplypath 106 which penetrates the rotating shaft 95 to supply the wafer withe.g. N₂-gas. The outer chamber 43 is equipped, on its top, with a N₂-gassupplier 107 to eject N₂-gas between the upper face of the top plate 72and the interior of the outer chamber.

As shown in FIG. 14, an “inner-cup” drain pipe 110 is connected with thebottom of the inner cup 70 to discharge liquid and droplets in the innercup 70. The “inner-cup” drain pipe 110 is movable up and down through athrough-port 111 formed on the bottom of the outer chamber 43. The lowerend of the “inner-cup” drain pipe 110 is inserted into an “inner-cup”mist trap 112. Owing to the provision of the “inner-cup” mist trap 112,it is possible to remove air-bubbles in the liquid and dropletsdischarged from the inner cup 70. The air bubbles on removal isdischarged through a mist-trap exhaust pipe 113 connected with the“inner-cup” mist trap 112. The liquid and droplets after the removal ofair bubbles is collected by an “inner-cup” waste-fluid collecting line114 connected to the “inner-cup” mist trap 112.

An “outer-chamber” drain pipe 115 is connected with the bottom of theouter chamber 43 to drain liquid and droplets therefrom. The drain pipe115 is provided with a “outer-chamber” mist trap 116 which eliminatesair bubbles from the liquid and droplets drained from the mist trap 116.The air bubbles on removal is discharged through a “outer-chamber”mist-trap exhaust pipe 117 connected with the “outer-chamber” mist trap116. The liquid and droplets after the removal of air bubbles iscollected by an “outer-chamber” waste-fluid collecting line 118connected to the “outer-chamber” mist trap 116.

When the inner cup 70 drops, there is realized a condition of FIG. 15where the spin chuck 71 and the wafer W held by the chuck 71 projectfrom the upper end of the inner cup 70 upward. Then, the liquid anddroplets in the outer chamber 43 moves down outside the inner cup 70 andis drained through the “outer-chamber” drain pipe 115. On the otherhand, when the inner cup 70 is elevated as shown in FIG. 14, there isrealized a condition that the inner cup 70 surrounds the spin chuck 71and the wafer W thereby to prevent the cleaning liquid etc. supplied toboth faces of the wafer W from splashing around. Then, the upper part ofthe inner cup 70 approaches the inner wall of the outer chamber 43, sothat the liquid and droplets in the inner cup 70 is drained through the“inner-cup” drain pipe 110.

Note, the substrate processing unit 13 of the cleaning system 1 has astructure similar to that of the substrate processing unit 12 and iscapable of cleaning of the back face of the wafer W, removal of theperipheral part of the surface of the wafer W and also cleaning of thesurface of the wafer W (Back-Bevel cleaning).

Further, the substrate cleaning units 14, 15 of the cleaning system 1are constructed so as to have the ability to clean both faces of thewafer W by various kinds of cleaning liquids and further dry the waferW.

Now, in the cleaning system 1 mentioned above, a not-shown transferrobot first lays the carriers C each accommodating the wafers W, forexample, twenty-five wafers W on the in/out port 4. Next, thepickup/accommodating arm 11 takes the wafers W out of the carrier C oneby one and successively delivers the wafer W to the main wafer transferunit 7. Next, by the transfer arm 34, the wafer W is suitably loadedinto the substrate processing unit 12 or 13, performing the cleaning ofthe back face of the wafer W, removal of the peripheral part of thesurface of the wafer W and also cleaning of the peripheral part of thewafer W. Further, the wafer W is suitably loaded into the substratecleaning unit 14 or 15 where contaminants, such as particles, stickingto the wafer W are cleaned for removal. In this way, the wafer W aftercompleting the designated cleaning process is suitably unloaded from thesubstrate processing units 12, 13 or the substrate cleaning units 14, 15by main wafer transfer unit 7. Subsequently, the wafers W is deliveredto the loaded pickup/accommodating arm 11 and successively accommodatedin the carrier C again.

Being representative of the substrate processing units 12, 13, we nowdescribe the processing operation at the substrate processing unit 12.As shown in FIG. 7, the mechanical shutter 46 of the substrateprocessing unit 12 opens at first, while the mechanical shutter 47 forthe outer chamber 43 also opens. Then, the transfer arm 34 carrying thewafer W enters the unit. The inner cup 70 is lowered to project thechuck body 73 relatively upward. In advance of that, the under plate 75is lowered to occupy the withdrawal position in the chuck body 73. Thetop plate 72 is elevated to occupy its withdrawal position in advance.Further, the shutter 50 for the edge-arm housing is closed.

The main wafer transfer unit 18 lowers the transfer arm 34 to deliverthe wafer W to the holding member 76. Then, the spin chuck 71 supportsthe wafer W by means of not-shown support pins while directing thewafer's surface for semiconductor devices upward. Then, since the underplate 75 has been moved to the withdrawal position and is apart from alevel (height) of the wafer W held by the spin chuck 71, the transferarm 34 allows the wafer W to be delivered to the spin chuck 71 withcomposure. After delivering the wafer W to the spin chuck 71, thetransfer arm 34 withdraws from the interior of the outer chamber 43 andthe interior of the mechanical shutter 46. After the withdrawal of thetransfer arm 34, both of the mechanical shutter 46 for the substrateprocessing unit 12 and the mechanical shutter 47 of the outer chamber 43are together closed.

The inner cup 70 is elevated into a condition to surround the chuck body73 and the wafer W. The under plate 75 rises up to the processingposition in the chuck body 73. As shown in FIG. 17, there is produced aclearance L1 (for example, a clearance on the order of 0.5-3 [mm])between the under plate 75 moved to the processing position and the backface of the wafer W held by the spin chuck 71.

Next, the cleaning process for the back face of the wafer W is carriedout. Through the lower supply path 100, the chemical liquid for cleaningis quietly fed onto the under plate 75 to supply the clearance L1 withthe chemical liquid for cleaning. By spreading the chemical liquid forcleaning over the whole lower face of the wafer W in the narrowclearance L1, there is formed a liquid film composed of the chemicalliquid for cleaning, which comes into uniform contact with the wholelower face of the wafer W. If the liquid film of chemical liquid forcleaning is formed all over the clearance L1, the supply of chemicalliquid for cleaning is stopped to clean the lower face of the wafer W.By filling the clearance L1 with the chemical liquid for cleaningthereby to form a liquid film, it is possible to prevent the breakdownin shape of the liquid film composed of the chemical liquid forcleaning, owing to the formation of surface tension. To the contrary, ifthe shape of liquid film of cleaning chemical collapses, then a problemof inferior cleaning arises in that the lower face of the wafer W mayinclude portions in no contact with the liquid film of cleaning chemicalor that the air bubbles may enter the liquid film. However, according tothe embodiment, since the narrow clearance L1 between the under plate 75and the lower face of the wafer W is filled up with the chemical liquidfor cleaning, it is possible to maintain the shape of liquid filmcomposed of the chemical liquid for cleaning, preventing the occurrenceof inferior cleaning.

In this case, the spin chuck 71 rotates the wafer W at a relatively-lowspeed (e.g. the order of 10 to 30 rpm) so as to maintain a shape of theliquid film of chemical liquid for cleaning. The rotation of the wafer Wcauses the generation of a liquid flow in the liquid film of chemicalliquid for cleaning. Owing to the generation of this liquid flow, itbecomes possible to prevent an occurrence of stagnation in the liquidfilm of chemical liquid for cleaning and also possible to improve thecleaning efficiency of the apparatus. The rotation of the wafer W may becarried out intermittently. For example, the wafer W is rotated for apredetermined period or at predetermined revolutions and thereafter, therotating operation of the spin chuck 71 is stopped for a predeterminedperiod thereby to bring the wafer W to a standstill. Subsequently, thewafer W is rotated again. In this way, the repetition of the wafer Wbetween rotation and standstill allows the chemical liquid for cleaningto diffuse all over the lower face of the wafer W with ease. Of course,it is also possible to perform the cleaning operation while maintainingthe wafer W at a standstill with no rotation. Further, once the liquidfilm is formed on the wafer W, there is no need to further supply thewafer W with new cleaning chemical. Because the whole lower face of thewafer W can be cleaned by the chemical liquid for cleaning which hasbeen already supplied between the under plate 75 and the lower face ofthe wafer W unless the shape of the liquid film of chemical liquid forcleaning collapses. On the other hand, when the shape of the liquid filmof chemical liquid for cleaning is likely to collapse, a new liquid issupplied to repair the shape of the liquid film of chemical liquid forcleaning appropriately. In this way, the consumption of the chemicalliquid for cleaning can be saved. Note, if the chemical liquid forcleaning is successively supplied through the lower supply path 100while dropping the liquid and droplets of the liquid film of chemicalliquid for cleaning from the margin of the under plate 75, then it ispossible to perform a preferable cleaning process using the chemicalliquid for cleaning by always replacing the inside of the liquid film ofchemical liquid for cleaning with a brand-new chemical liquid forcleaning. Also in this case, it is desirable to supply a new liquid asquiet as possible in view of saving the consumption of the chemicalliquid for cleaning.

On the other hand, when forming the liquid film by filling the clearanceL1 with the chemical liquid for cleaning, it is carried out to allow thechemical liquid to make a detour to the surface's side of the wafer W (asurface of the metallic film 141) via the peripheral part of the backface of the wafer W, thereby supplying the chemical liquid for cleaningup to the peripheral part on the surface of the wafer W, as the objectto be eliminated in the later-mentioned removal process. Then, thecleaning process of the peripheral part on the surface of the wafer W iscarried out at the same time of the cleaning process of the back face ofthe wafer W.

Subsequently, the spin chuck 71 rotates, for example, at 2,000 rpm forfive seconds. As a result, the chemical liquid for cleaning is shakendown from the wafer W and continuously drained into the “inner-cup”drain pipe 110. When the spin chuck 71 rotates at a high speed, the(three) holding member 76 on the chuck body 73 are brought into acondition of FIG. 10 respectively. That is, the lower part of the pusherarm 81 abuts against the inside of the chuck body 73. Therefore, since agrasping force for the wafer W originates in the spring 82 during thehigh-speed rotation, the wafer W is not subjected to an excessiveholding force.

Next, it is carried out to supply N₂-gas between the under plate 75 andthe lower face of the wafer W through the lower supply path 100, forexample, for 10 seconds in order to discharge an atmosphere of thechemical liquid below the wafer W. The supply of N₂-gas allows thedroplets of the chemical liquid to be removed from the back face of thewafer W.

Next, the top plate 72 moves to a position adjacent to the upper face ofthe wafer W. The shutter 50 for edge-arm housing opens and the edge arm60 moves to the upside of the peripheral part of the wafer W carried bythe spin chuck 71. When the edge arm 60 reaches a designated position,the N₂-gas nozzle 63 on the arm 60 begins the supply of N₂-gas andsuccessively, the chemical nozzle 61 begins the supply of the chemicalliquid. Then, there is performed a peripheral-part removing process toremove the corner of the metallic film 141 laminated on the surface ofthe wafer W.

During the peripheral-part removing process, the spin chuck 71 rotatesat revolutions of the order of 300 rpm, for example. As mentionedbefore, since three holding members 76 are brought into a condition ofFIG. 9 respectively, an appropriate holding force against the wafer W isproduced, so that the spin chuck 71 can rotate the wafer W.

As the tip of the chemical nozzle 61 directs the circumference of thewafer W, the ejected chemical liquid flows to the outside of the wafer Wsmoothly. The chemical liquid supplied from the chemical nozzle 61 isswept away toward the circumference of the wafer W by N₂-gas suppliedfrom the N₂-gas nozzle 63. As the tip of the N₂-gas nozzle 63 directsthe circumference of the wafer W, N₂-gas supplied from the N₂-gas nozzle63 allows the chemical liquid to be swept away toward the circumferenceof the wafer W effectively. It is noted that, on the surface of thewafer W (surface of the metallic film 141), the area 66 on chemicalsupply and the area 66′ on chemical flow are together included in thearea 68′. Additionally, since the N₂-gas nozzle 63 begins the supply ofN₂-gas before starting the supply of the chemical liquid by the chemicalnozzle 61, there is no possibility that the chemical liquid suppliedfrom the chemical nozzle 61 flows toward the center of the wafer W. Onthe other hand, the so-swept chemical liquid, N₂-gas and the chemicalatmosphere generated at processing are all sucked for discharge in thecircumference of the wafer W by the suction nozzle 65. Further, thecover plate 64 carrying the chemical nozzle 61 and the N₂-gas nozzle 63prevents the chemical liquid from splashing to the inside face of thewafer W. Additionally, by collecting the chemical liquid, which has beenswept away by N₂-gas, and successively applying an appropriate treatmenton the chemical liquid, it can be reused with ease.

During the peripheral-part removing process, the top plate 72 is loweredto a position of FIG. 17 (processing position) and N₂-gas is suppliedthrough the upper supply path 106. The N₂-gas through the upper supplypath 106 prevents the chemical liquid supplied from the chemical nozzle61 and the chemical atmosphere generated during the peripheral-partremoving process from flowing into the center face of the wafer W. Inthis way, N₂-gas supplied from the N₂-gas nozzle 63 prevents thechemical liquid from flowing on the wafer's surface on N₂-gas supply andalso flowing outside the flowing the wafer's surface on N₂-gas flowing.Further, N₂-gas supplied from the upper supply path 106 prevents thechemical liquid from flowing into the center face of the wafer W.Therefore, it is possible to prevent the chemical liquid from flowinginto the inside face of the wafer W effectively. Additionally, thesupply of N₂-gas through the upper supply path 106 has an effect toprevent an occurrence of water-marks on the wafer W.

Again, during the peripheral-part removing process, the N₂-gas supplier107 at the top of the outer chamber 43 supplies N₂-gas onto the topplate 72 thereby to form downward flows of N₂-gas. Since a space betweenthe upper face of the top plate 72 and the outer chamber 43 is filled upwith N₂-gas, the chemical atmosphere that rises about the top plate 72as a result of evaporation of the liquid film of the chemical liquiddoes not invade the space above the top plate 72. Therefore, it ispossible to prevent the chemical liquid from remaining in the upper partof the outer chamber 43 after the peripheral-part removing process.

When the peripheral-part removing process is completed, the chemicalnozzle 61 stops the supply of the chemical liquid. The N₂-gas nozzle 63still maintains the supply of N₂-gas and subsequently, the pure-waternozzle 62 starts the supply of pure water. In this way, theperipheral-part rinsing process to supply the peripheral part of thewafer W with pure water is started. As the tip of the pure-water nozzle62 directs the circumference of the wafer W, the ejected pure waterflows to the outside of the wafer W smoothly. The pure water suppliedfrom the pure-water nozzle 62 is swept away toward the circumference ofthe wafer W by N₂-gas supplied from the N₂-gas nozzle 63. As the tip ofthe N₂-gas nozzle 63 directs the circumference of the wafer W, N₂-gassupplied from the N₂-gas nozzle 63 allows the pure water to be sweptaway toward the circumference of the wafer W effectively. It is notedthat, on the surface of the wafer W (surface of the metallic film 141),the area 66 on pure-water supply and the area 66′ on pure-water flow aretogether included in the area 68′. Additionally, since the N₂-gas nozzle63 begins the supply of N₂-gas before starting the supply of the purewater by the pure-water nozzle 62, there is no possibility that the purewater supplied from the pure-water nozzle 62 flows toward the center ofthe wafer W. On the other hand, the so-swept pure water, N₂-gas and avapor atmosphere generated at processing are all sucked for discharge inthe circumference of the wafer W by the suction nozzle 65. Further, thecover plate 64 carrying the pure-water nozzle 62 and the N₂-gas nozzle63 prevents the pure water from splashing to the inside face of thewafer W. On the other hand, the lower supply path 100 supplies aclearance between the under plate 75 and the lower face of the wafer Wwith pure water, performing the back-face rinsing process. In this way,by rinsing both peripheral part and back face of the wafer W, thechemical liquid is washed from the wafer W.

Also in the rinsing process, the top plate 72 is lowered to theprocessing position and N₂-gas is supplied through the upper supply path106. The N₂-gas through the upper supply path 106 prevents the purewater supplied from the pure-water nozzle 62 and the vapor atmospheregenerated during the peripheral-part rinsing process from flowing intothe center face of the wafer W. In this way, N₂-gas supplied from theN₂-gas nozzle 63 prevents the pure water from flowing on the wafer'ssurface on N₂-gas supply and also flowing outside the flowing thewafer's surface on N₂-gas flowing. Further, N₂-gas supplied from theupper supply path 106 prevents the pure water from flowing into thecenter face of the wafer W. Therefore, it is possible to prevent thepure water from flowing into the inside face of the wafer W effectively.Additionally, the supply of N₂-gas through the upper supply path 106 hasan effect to prevent an occurrence of water-marks on the wafer W.

When the rinsing process is completed, the supply of pure water throughthe pure-water nozzle 62 and the lower supply path 100 is stopped. TheN₂-gas nozzle 63 continues to supply the circumference of the wafer Wwith N₂-gas, executing the peripheral-part drying process. As the tip ofthe N₂-gas nozzle 63 directs the circumference of the wafer W, N₂-gas iseasy to flow to the outside of the wafer W. Then, the suction nozzle 65sucks N₂-gas for its discharge. On the other hand, the lower supply path100 supplies a clearance between the under plate 75 and the lower faceof the wafer W with N₂-gas thereby to carry out the back-face dryingprocess. In the above way, both peripheral part and back face of thewafer W are dried. After completing the peripheral-part drying processand the back-face drying process, the supply of N₂-gas through theN₂-gas nozzle 63 and the lower supply path 100 is stopped, while the topplate 72 is elevated up to a position apart from the upper face of thewafer W. Next, the wafer W is rotated at a high speed (e.g. the order of1500 rpm) in comparison with a rotating speed in the drying process,performing a spin drying process.

After the spin drying process, the edge arm 6.0 moves into the edge-armhousing 44 and the shutter 50 for edge-arm housing is closed. Next, thewafer W is discharged from the substrate processing unit 12. Themechanical shutter 46 for the substrate processing unit 12 opens and themechanical shutter 47 for the outer chamber 43 opens as well. Then, thetransfer arm 34 of the wafer transfer arm 18 enters into the unit 12 tosupport the lower face of the wafer W. Next, the transfer arm 34receives the wafer W from the support pins of the spin chuck 71 andcontinuously withdraws from the unit 12. During this process, since theunder plate 75 is positioned at the withdrawal position, there isproduced a sufficient clearance between the under plate 75 and the waferW held by the spin chuck 71, allowing the transfer arm 34 to receivefrom the spin chuck 71 with composure.

According to the substrate processing apparatus 12 mentioned above,during the peripheral-part removing process, it is possible to sweepaway the chemical liquid outside of the wafer W effectively. Further,the apparatus 12 prevents the chemical liquids, the pure water, thechemical atmosphere and the vapor atmosphere from flowing into thecenter face of the wafer W. During the peripheral-part rinsing process,the apparatus is capable of sweeping away the pure water outside of thewafer W effectively. Additionally, it is possible to dry the wafer'sface onto which the pure water has been supplied. Despite that the spinchuck 71 rotates at a high speed, the wafer W is not subjected to anexcessive holding force.

The above is one example of preferred embodiments in accordance with thepresent invention; nevertheless the invention is not limited to theabove-mentioned embodiment only. For example, as shown in FIG. 18, theunit chamber 42 may be provided, on a top thereof, with a fan filterunit (FFU) 122 and also provided, on the lower part, with an exhaustmechanism 123. In this case, even if a processing liquid atmosphere inthe outer chamber 43 leaks out, the atmosphere is discharged from theunit chamber 42 owing to the provision of downward flows produced by theFFU 122 and the exhaust mechanism 123. Therefore, there is not muchlikelihood that the wafer W is contaminated by the processing liquidatmosphere when unloading the processed wafer W. Additionally, there isnot much likelihood that the processing liquid atmosphere leaks out ofthe unit chamber 42.

Further, as shown in FIG. 19, the top plate 72 may be provided with arecess 125. Then, if the processes of removing, rinsing and drying theperipheral part of the wafer W are performed while accommodating theedge arm 60 in the recess 125, the top plate 72 can cover all the facesof the wafer W except the wafer's faces during the supply of chemicalliquid or pure water. Thus, even if the chemical liquid or the purewater scatters, it is possible to prevent the droplets of splash fromadhering to the faces of the wafer W except the wafer's faces during thesupply of chemical liquid or pure water.

During the process of removing the peripheral part of the wafer W, thepure-water nozzle 62 may supply pure water as the inert processing fluidin place of supplying N₂-gas through the N₂-gas nozzle 63. In this case,the pure water supplied onto the area 67 (FIG. 6) flows on the surfaceof the wafer W (the surface of the metallic film 141) while directingthe periphery of the wafer W, providing the fan-shaped flowing area 67′.On the surface of the wafer W (the surface of the metallic film 141),the area 66 on the chemical supply and the flowing area 66′ are togetherincluded in the area 67′. Additionally, the pure-water nozzle 62 beginsthe supply of pure water in advance of the supply of chemical liquid bythe chemical nozzle 61. Therefore, there is no fear that the chemicalliquid through the chemical nozzle 61 flows toward the center of thewafer W. Additionally, owing to the supply of N₂-gas through the uppersupply path 106 of the top plate 72 lowered to the processing position,it is possible to prevent the chemical liquid and the pure water fromflowing into the inside face of the wafer W effectively. Note, in orderto make sure that the chemical liquid and the pure water are swept awayby the pure water flowing in the form of the area 67′, it is desirablethat the area 67 of pure-water supply is wider than either of the area66. That is, as shown in FIG. 6, it is carried out to supply the purewater in a manner that a width of the area 67′ in the circumferentialdirection of the wafer W gets broader a width of the area 66′. Further,during the process of rinsing the peripheral part of the wafer W, thepure-water nozzle 62 may supply pure water as the inert processing fluidin place of supplying N₂-gas through the N₂-gas nozzle 63. Also in thiscase, owing to the supply of N₂-gas through the upper supply path 106 ofthe top plate 72 lowered to the processing position, it is possible toprevent the pure water from flowing into the inside face of the wafer W.Again, during the process of removing the peripheral part of the waferW, the N₂-gas nozzle 63 may supply N₂-gas or the pure-water nozzle 62may supply the pure water in place of supplying N₂-gas through the uppersupply path 106 of the top plate 72. Also in this case, since eitherN₂-gas supplied through the N₂-gas nozzle 63 or pure water suppliedthrough the pure-water nozzle 62 sweeps away the pure water whilecontrolling the flow, it is possible to prevent the pure water fromflowing into the inside face of the wafer W. Further, during the processof rinsing the peripheral part of the wafer W, the N₂-gas nozzle 63 andthe pure-water nozzle 62 may supply N₂-gas and the pure waterrespectively in place of supplying N₂-gas through the upper supply path106 of the top plate 72. Also in this case, since N₂-gas suppliedthrough the N₂-gas nozzle 63 sweeps away the pure water whilecontrolling the flow, it is possible to prevent the pure water fromflowing into the inside face of the wafer W.

The edge arm 60 may be provided with the chemical nozzle 61 and thepure-water nozzle 62 except the N₂-gas nozzle 63. Also in this case, itis possible to prevent the chemical liquid, which has been suppliedthrough the chemical nozzle 61 during the removal process of theperipheral part of the wafer W, from flowing into the inside face of thewafer W. Additionally, owing to the supply of N₂-gas through the uppersupply path 106 of the top plate 72 during the rinsing process of theperipheral part of the wafer W, it is possible to prevent the pure waterfrom flowing into the inside face of the wafer W. Alternatively, theedge arm 60 may be provided with the chemical nozzle 61 and the N₂-gasnozzle 63 except the pure-water nozzle 62.

The edge arm 60 may be constructed so as to be movable in the radialdirection of the wafer W. Namely, the edge arm 60 may be moved whilemaintaining the relationship of FIG. 6 among the flows of the processingfluids. Then, it becomes possible to change a width of the wafer's faceto be processed in the peripheral part of the wafer W. Additionally, itis possible to perform the processing for the wafer W with the chemicalliquid in correspondence with a distance from the circumference of thewafer W in multistage. For example, as shown in FIG. 20, it is possibleto eliminate the metallic film 141 so as to get thinner as approachingthe periphery of the wafer W. Then, since either N₂-gas or pure waterprevents progress of the chemical liquid flowing inside the wafer W, itis possible to move the edge arm 60 from the inside of the wafer W tothe periphery. In this way, owing to the terraced formation of thecorner of the metallic film 141, it can be peeled from the wafer W withdifficulty. When the device structure has films formed in multi-layer(like the films 141 a, 141 b, 141 c of FIG. 20), it is preferable togradually narrow the width of each film to be eliminated from theperiphery of the wafer W as the film is being lowered. Consequently, themetallic film 141 gets thinner as approaching the periphery of the waferW.

The present invention is applicable to not only a substrate processingapparatus to which the cleaning liquid is supplied but also a substrateprocessing apparatus for the application of other treatments on thesubstrate besides both removal of the peripheral part of the substrateand cleaning thereof. Additionally, a substrate as the object to beprocessed is not limited to a semiconductor wafer only. Thus, thesemiconductor may be replaced with the other substrate, for example,substrate for LCD glass, CD substrate, print base plate, ceramicsubstrate, etc.

According to the present invention, one processing fluid supplied fromthe inside fluid supplier can sweep away another processing fluid (forexample, chemical liquid) supplied from the outside fluid supplier, in adirection apart from the center of the substrate. Therefore, it ispossible to process the peripheral part of the substrate withoutprocessing the central portion of the substrate. Further, it is possibleto change the width of the substrate's surface to be processed. Still,it is possible to prevent the processing fluid from splashing on thesubstrate's surface requiring no processing.

What is claimed is:
 1. A substrate processing apparatus comprising: anannular substrate holder configured to hold a substrate, the substrateholder having a circumference; an annular top plate disposed above thesubstrate holder, and movable between a first position, where the topplate is located adjacent to an upper surface of the substrate held bythe substrate holder, and a second position where the top plate isremote from the upper surface of the substrate held by the substrateholder; and a chemical liquid nozzle provided to discharge a chemicalliquid onto a peripheral portion of the upper surface of the substrateheld by the substrate holder; and wherein the top plate is provided withan inert gas supply path for supplying an inert gas to a space betweenthe top plate and the substrate held by the substrate holder, the inertgas supply path has an open end serving as an inert gas supply port forsupplying the inert gas into the space, and the open end is located in acenter portion of the top plate so as to face a center portion of theupper surface of the substrate held by the substrate holder when the topplate is in the first position, wherein the top plate has acircumference sized so as to substantially cover the substrate holderwhen the top plate is in the first position and, wherein the top platehas an opening therein for accommodating the chemical liquid nozzle asthe nozzle discharges the chemical liquid onto the peripheral portion ofthe substrate when the top plate is in the first position, and theopening is provided in a peripheral portion of the top plate so that achemical liquid discharge port of the chemical liquid nozzleaccommodated in the opening is located above the peripheral portion ofthe substrate to face the peripheral portion of the substrate when thetop plate is in the first position.
 2. The apparatus according to claim1, wherein the chemical liquid nozzle is movable between a firstposition adjacent to the peripheral portion of the upper surface of thesubstrate held by the substrate holder, and a second position where thechemical liquid nozzle is withdrawn from a space above the upper surfaceof the substrate held by the substrate holder, the chemical liquidnozzle being in its first position when the top plate is in its firstposition, and the chemical liquid nozzle being in its second positionwhen the top plate is in its second position.
 3. The apparatus accordingto claim 1, further comprising an enclosure structure defining therein aclosed space accommodating the chemical liquid nozzle and the top plate.4. The apparatus according to claim 3, wherein an opening allowing thesubstrate to be loaded into and unloaded from the closed space definedin the enclosure structure is provided on the enclosure structure, andwherein a shutter for closing the opening is provided at the opening. 5.The apparatus according to claim 3, further comprising a N₂ gas supplierthat supplies N₂ gas from an upper portion of the enclosure structureinto the closed space.
 6. The apparatus according to claim 1, furthercomprising a pure water nozzle that positions, as viewed from above,nearer to a center of the substrate held by the substrate holder thanthe chemical liquid nozzle, to supply pure water onto the upper surfaceof the substrate.
 7. The apparatus according to claim 6, wherein thechemical liquid nozzle is inclined such that the chemical liquid jettedfrom the chemical liquid nozzle is directed toward outside the substrateheld by the substrate holder.
 8. The apparatus according to claim 6,further comprising an inert gas nozzle that positions, as viewed fromabove, nearer to a center of the substrate held by the substrate holderthan the pure water nozzle, to supply inert gas onto the upper surfaceof the substrate.
 9. The apparatus according to claim 1, furthercomprising a spin chuck having a chuck body and a plurality of holdingmembers arranged at angular intervals which hold the peripheral part ofthe substrate.